A conventional inverter control device for driving a DC motor of an air conditioner executes control to prevent the DC motor from discontinuing the operation due to a loss of synchronization. More specifically, the inverter control device controls the operation of the DC motor in such a manner that a primary current, input to a converter unit that converts an AC voltage from a commercial AC power supply to a DC voltage, does not exceed the current data that is determined as a synchronization-loss limit value for certain given conditions. With this control, the conventional inverter control device achieves a stable operation of a DC motor.